The present invention relates to a door handle assembly and, in particular, a key-actuated interchangeable lock core supported in a hollow doorknob or the like. More particularly, the present invention relates to a door handle assembly having a unitary core retainer sleeve for supporting an interchangeable lock core in a hollow doorknob.
Machined doorknobs made by machining solid brass stock are known. Machined brass doorknobs provide a great measure of security and accept interchangeable lock cores and other lock-actuating linkages as shown, for example, in U.S. Pat. Nos. 4,437,695; 4,435,967; 4,428,570; 4,428,212; 4,394,821; 4,342,478; and 4,312,201. The outer end opening in a machined knob is generally closed by a separate face plate carrying an inwardly extending boss which forms a seat for an interchangeable lock core as shown, for example, in U.S. Pat. No. 4,342,478 to Foshee.
Stamped doorknobs can provide satisfactory security in many applications and are less costly to produce than machined knobs. However, a shortcoming of conventional stamped doorknobs is that they do not include easily assembled means for holding a lock core in the hollow region of the stamped doorknob.
An object of the present invention is to provide a unitary core retainer sleeve for supporting an interchangeable lock core in its proper place inside a stamped hollow doorknob.
Another object of the present invention is to provide a core retainer sleeve which is configured to support an interchangeable lock core and mount directly on conventional lock chassis so that the door handle assembly of the present invention can be retrofitted onto an existing lock chassis to serve as a replacement for a conventional door handle unit.
According to the present invention, a door handle assembly includes a hollow knob shell having a front face and an interior cavity having a front opening in the front face, a lock core, and a unitary core retainer sleeve situated inside the interior cavity and coupled to the knob shell. The lock core has a front end formed to include a keyway opening. The unitary core retainer sleeve is formed to include means for supporting the lock core inside the interior cavity so that the front end of the lock core is positioned to lie in the front opening of the knob shell to permit a user to insert a key into the keyway passage opening.
In preferred embodiments, the core retainer sleeve includes a forwardly presented edge facing toward the front opening formed in the front face of the knob shell. The forwardly presented edge defines a lock core-receiving opening in the core retainer sleeve which communicates with the front opening in the knob shell. The front end of the lock core includes a rearwardly presented edge engaging the forwardly presented edge of the core retainer sleeve to limit movement of the lock core into the interior cavity provided in the knob shell. Once the edge on the lock core engages the edge on the core retainer sleeve, the lock core is fully supported in a cradle formed in the sleeve and situated in a proper location relative to the knob shell and its front opening.
The unitary core retainer sleeve also includes a rearwardly presented surface for anchoring the lock core in its proper position in the knob shell. The lock core is a key-actuated interchangeable core of the type including a core body and a control lug movable relative to the core body to control the release of the lock core from its place in the core retainer sleeve. The control lug normally occupies a core-blocking position engaging the rearwardly presented surface of the sleeve to block removal of the lock core from the core retainer sleeve through the lock core-receiving opening. The control lug is movable from its normal position to a core-releasing position disengaging the rearwardly presented surface to permit removal of the lock core from the retainer sleeve through the lock core-receiving opening. The control lug is moved relative to the core body using a control key inserted into the keyway provided in the interchangeable lock core. A separate operating key is usable to control locking and unlocking the door handle assembly itself.
Additional objects, features, and advantages of the invention will become apparent to those skilled in the art upon consideration of the following detailed description of a preferred embodiment exemplifying the best mode of carrying out the invention as presently perceived.